Human hair becomes soiled due to its contact with the surrounding environment and from the sebum secreted by the scalp. The soiling of hair causes it to have a dirty feel and an unattractive appearance. The soiling of the hair necessitates shampooing with frequent regularity.
Shampooing cleans the hair by removing excess soil and sebum. However, shampooing can leave the hair in a wet, tangled, and generally unmanageable state. Once the hair dries, it is often left in a dry, rough, lusterless, or frizzy condition due to removal of the hair's natural oils and other natural conditioning and moisturizing components. The hair can further be left with increased levels of static upon drying, which can interfere with combing and results in a condition commonly referred to as "fly-away hair."
A variety of approaches have been developed to alleviate these after-shampoo problems. These approaches range from post-shampoo application of hair conditioners such as leave-in and rinse-off products, to hair conditioning shampoos which attempt to both cleanse and condition the hair from a single product. Hair conditioners are typically applied in a separate step following shampooing. The hair conditioners are either rinsed-off or left-in, depending upon the type of product used. Hair conditioners, however, have the disadvantage of requiring a separate and inconvenient treatment step. Conditioning shampoos, i.e. shampoos which both cleanse and condition the hair, are highly desirable products because they are convenient for consumers to use.
In order to provide hair conditioning benefits in a cleansing shampoo base, a wide variety of conditioning actives have been proposed. However, many of these actives have the disadvantage of leaving the hair feeling soiled or coated, of interfering with the cleansing efficacy of the shampoo, or of yielding a resultant shampoo with poor shelf stability.
It has surprisingly been found in the present invention that highly stable shampoo compositions can be achieved utilizing a stabilizing surfactant system comprising a surfactant selected from the group consisting of anionic amino acid derivative surfactants, amphoteric surfactants, cationic surfactants, and mixtures thereof. This stabilizing surfactant system is used in the present invention in combination with a detersive anionic surfactant, certain fatty compounds, and certain hair conditioning agents, to provide compositions having improved wet hair conditioning benefits such as smoothness and ease of combing compared to conventional conditioning shampoos. These compositions also provide improved dry hair conditioning benefits such as leaving the hair feeling soft, smooth, and moistened. These dry hair benefits can also provide hair that looks shiny.
It is therefore an object of the present invention to provide conditioning shampoo compositions, i.e. compositions which both cleanse and condition the hair from a single product.
It is another object of the present invention to provide compositions which are stable.
It is another object of the present invention to provide compositions which do not leave the hair feeling coated, heavy, or soiled.
It is another object of the present invention to provide compositions which provide improved wet hair conditioning benefits such as smoothness and ease of combing.
It is another object of the present invention to provide compositions which provide improved dry hair conditioning benefits such as leaving the hair feeling soft, smooth, moist and looking shiny.
It is another object of the present invention to provide methods for cleansing and conditioning the hair utilizing a single composition.
These and other objects will become readily apparent from the detailed description which follows.